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  1. bwDraco

    Nitecore MH20 - first impressions and a thermal image

    I was looking for a smaller 18650 light at B&H Photo a few days ago (my SRT7GT is too big to put in my bag or keep on my belt these days) and wound up picking up a new Nitecore MH20, with a new Nitecore NL1834 battery to go with it. This isn't the newer MH20GT with the XP-L emitter; I wanted...
  2. bwDraco

    Observations on the Nitecore SRT7GT as compared to the old SRT7

    Moderators: Although this is more of a comparison than a true review, feel free to move this to the flashlight reviews forum if you think it's more appropriate there. So I just got a Nitecore SRT7GT to replace my busted SRT7. If you're not familiar with the SRT7, I encourage you to read my...
  3. bwDraco

    Nitecore SRT7 still turns on after getting brutally smashed

    My Nitecore SRT7 was brutally smashed onto a vinyl floor during an altercation today (would rather not go into detail). The glass lens was shattered and the tailcap deformed. :eek: Yet the light turns on and all modes function properly. :faint: The battery was essentially unscathed, which I...
  4. bwDraco

    Drove 5V into a Li-ion cell for just one second, should I be worried?

    While testing a faulty device, I unexpectedly drove 5V USB into a protected NCR18650B cell for about one second. The voltage of the cell itself did not exceed 4.3V, which is inside the 4.35V safety limit, and settled to below 4.1V when power was removed, but I'm not sure if the cell is still...
  5. bwDraco

    Laptop batteries: Why don't they use better cells?

    A lot of laptop batteries I encounter seem to use 2600 mAh cells. For example, the ones for my gaming laptop are rated at 14.8V 5200 mAh, or a 4S2P pack using 3.7V 2600 mAh cells, for a total of about 77 Wh of energy. With better battery technology available, why don't computer manufacturers...
  6. bwDraco

    Lithium-ion over-discharge concerns and questions: Absolute minimum voltage?

    I managed to over-discharge a 2-cell DSLR battery to about 5.1 volts open-circuit (2.55 volts per cell). The battery seems to be charging normally and was never discharged to less than 2.4 volts per cell under load. The battery was discharged to this level for less than 30 minutes. I know it's...
  7. bwDraco

    Nitecore UM10—high termination current? Charging stops at 200 mA

    I just got a Nitecore UM10, and while it's pretty good as a pure charger—gotta love that charge percentage display—I think there's a problem with the charger terminating at a high current, thereby not fully charging the battery. (The USB passthrough isn't working as expected, but that's not a...
  8. bwDraco

    Will charging at 1000 mA significantly reduce battery service life over 500 mA?

    My current chargers output 500 mA, which is a bit too slow for my taste, so I have a faster 1000 mA charger (Nitecore UM10) coming. Out of curiosity, will using this faster charger substantially reduce service life over a slower 500 mA charger? Should I prefer the slower charger whenever...
  9. bwDraco

    Broke my Nitecore SRT7, get another one or pick something else? Need quick help

    I know this is stupid, but I somehow managed to drop my SRT7 onto porcelain from about 3-4 feet and broke the primary LED driver. The main LED now only wants to work if I hit the head hard. This was during maintenance and the battery was removed, so it wasn't damaged by this event.:mecry: I...
  10. bwDraco

    XTAR MC1 charger—works well even with low inputs

    I just tried using my XTAR MC1 Li-ion battery charger (which is USB-powered) with my jury-rigged solar panel charger and I've noticed interesting behavior (in a good sense) when the input is very low (e.g. dim light). It turns out the charger drops to a special low-power mode for these...
  11. bwDraco

    Storing 18650s below freezing?

    I have an extra 18650 (Nitecore NL189 protected, based on Panasonic NCR18650B) which will be held in storage until needed. This battery is already charged to the correct state of charge (3.6V, about 40%). Would it be okay if I stored it below freezing continuously for several months? Will there...
  12. bwDraco

    ExtremeBeam Anti-Recoil system--does it live up to its claims?

    While I was at B&H a couple of days ago, I saw a few ExtremeBeam lights which had some proprietary "Anti-Recoil" system. The packaging claimed that the light could handle recoil up to .50 BMG. One thing for sure is that their impact resistance rating is a bit higher than most of the other...
  13. bwDraco

    XM-L2 lumen maintenance after 3000 hours: 98+%!

    I was wondering how well LEDs kept their brightness over continued use, and I came across this Cree document which specifies lumen maintenance test results. On page 30, I noticed that XM-L2 LEDs maintained upwards of 98% of their brightness after 3000 hours of operation. 98% after 3000 hours...
  14. bwDraco

    Nitecore SRT7 Revenger (1x18650, XM-L2 T6, 960lm) review

    Moderators: This thread is intended for the Flashlight Reviews forum. I've been carrying my Fenix LD20 day-in, day-out for close to three years, and it still works like a charm. More recently, though, I've been thinking about upgrading to 18650 to get better performance and runtime. After a...
  15. bwDraco

    Nitecore Intellicharger i2 reliability question

    I'm planning on getting my first 18650 light (locally from B&H, the famous camera store), a Fenix PD35 (single 18650, XM-L2, 850lm), along with a Fenix ARB-L2S (3400mAh) battery. I'm looking into the buying the Nitecore Intellicharger i2 for charging, but I've heard some bad things about this...
  16. bwDraco

    Li-ion pack discharged to ~1.6 V a cell for less than an hour--should I be concerned?

    I accidentally discharged a DeWalt 20V Max power tool battery (2 Ah) to about 8 volts open-circuit voltage (1.6 volts per cell) for a brief (<45 minutes) period with a load of less than 1 amp. Surprisingly, the battery did not cut off automatically and seems to lack overdischarge protection...
  17. bwDraco

    18650s taken from no-name USB charger measured at <2.7 V, should I keep them?

    I just took apart a cheap Chinese USB charger I no longer use and found a couple of 18650 cells. However, my multimeter is reading an unusually low voltage of 2.68 volts from each of these batteries. Should I keep them for future use, or just recycle them at the local Best Buy? (I presently...
  18. bwDraco

    Fenix new two-button UI seen across the product line--your thoughts

    I've noticed that Fenix has decided to adopt their two-button UI across the product line, from the LD22 to the PD22 to the TK35. This UI consists of a tactical forward clicky switch in the back of the light and a mode button either on the front or on the back, depending on the model. The mode...
  19. bwDraco

    Fenix LD20 review, almost 18 months later (picture heavy)

    Moderators: This thread is intended for the Reviews forum. Introduction The Fenix LD20 is a 2-AA powered, Cree XP-G based flashlight. I've been using this light for almost 18 months, and while this light has been superseded by the LD22, it remains a very capable light with decent (though not...
  20. bwDraco

    Hello, fellow flashlight enthusiasts

    Hello, fellow flashlight enthusiasts, I'm DragonLord. You might know me as the regular on Stack Exchange, or as a member of Pentax Forums. Whatever the case, it's nice to be part of a friendly flashlight community. :) While I'm not really a flashlight collector, I enjoy using high-quality...
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